LAUSR

Dear Editor, Lichen striatus (LS) is an uncommon, self-limited, linear inflammatory dermatosis that primarily occurs in children between the ages of 4 months and 15 years (Thomas et al., 2012). Physicians usually overlook nail involvement of LS due to its rarity and benign course of the disease (Kim et al., 2015). A 15-year-old boy presented with a 1-month history of linear scaly erythematous papules and plaques on the left lower extremity without any subjective symptoms. The skin lesion was located from the left thigh to the dorsum of a foot in a linear arrangement along Blaschko's line (Figure 1). A biopsy specimen from left ankle revealed lymphocytic infiltration in a lichenoid pattern and epidermal changes including irregular acanthosis and exocytosis of lymphocytes. He was diagnosed with LS and treated with topical corticosteroids and topical tacrolimus. Twelve weeks after his initial visit, the cutaneous lesion became almost clear but onychodystrophy which might be delayed presentation of nail matrix involvement developed at the left great toe nail (Figure 2). The patient denied any trauma and both direct microscopy examination of a potassium hydroxide preparation and fungus culture was negative. We used the same topical agents for 2 months more, considering self-limited natures of LS but onychodystrophy was aggravated without recurrence of the skin lesion. We began to treat him with intralesional injection (ILI) of 2.5 mg/ml triamcinolone acetate (TA) at 2-week intervals. Two points (medial and lateral) along the proximal nail fold by targeting nail matrix were injected until temporary